The organometals have numerous applications in industrial and occupational settings. The neurotoxicity of these agents, particularly organoleads and tins, is well known. However, their precise sites and mechanisms of action are poorly understood. The purpose of these studies is to characterize the neurophysiological effects of relevant organometals in an attempt to determine the site of action and aid in determining the mechanism of action of selected organometals. We have found that triethyl lead (TEL), but not trimethyl lead, triethyl tin or trimethyl tin markedly increases the sensitivity to pentylenetetrazol induced seizures. This increase in sensitivity is most pronounced in animals receiving multiple pentylenetetrazol injection. There is little, if any, change in sensitivity to a single dose of pentylenetetrazol. In addition, we have found that TEL accelerates amygdaloid kindling. On the other hand, it reduces the severity of seizures induced by electroconvulsive shock delivered via ear electrodes. These results indicate that (1) TEL produces a clear increase in seizure susceptibility, (2) the mode of eliciting the seizures is critical for observing the effect, and (3) suggest possible involvement of the limbic system in the toxicity of the compound. This project is being terminated.